This invention relates to microwave ovens and more particularly to a microwave oven wherein a removable meal supporting rack is provided. It is common in microwave ovens to provide a rack system wherein food to be cooked may be arranged at different levels in the oven cavity. Generally, these systems incorporate removable racks that can be selectively placed in the cavity at different levels. When metal racks are used they may absorb a substantial amount of wave energy supplied to the oven and also may distort the electric and magnetic field patterns so as to cause uneven cooking. Metal racks must therefore be designed and located in the oven cavity relative to the conductive path length and operating microwave frequency of the oven so as to not distort the cooking pattern or induce arcing at the walls of the oven. Generally the rack must be removed from its designated position in the oven whenever the food to be cooked is of a size and shape that would cause the rack to interfere with the placement of the food in the oven. Often the user of the rack, rather than remove and store the rack, will place the rack on the bottom wall of the oven and place the food to be cooked on the rack. The placement of the rack in an undesignated position relative to the conductive path length and operating microwave frequency of the oven can cause arcing of the rack to the cavity walls and overheating in the oven which in some instances potentially creates cavity fires.
By this invention there is provided a rack arrangement for microwave ovens in which use of the rack is discouraged in an undesignated area of the oven and must be removed from the oven for storing when not in use.